1. Field of the Invention
The present invention relates to a fabrication method for thin film electroluminescent panels used for displaying character and graphic images and more particularly to a forming method of back electrodes and lead-out electrodes.
2. Description of Related Art
Conventionally, there has been known an X-Y matrix display panel as a solid display panel using electroluminescent devices. In this panel, horizontal electrodes and vertical electrodes are arranged on respective surfaces of an electroluminescent layer so as to be orthogonal to each other and the electroluminescent layer emits light at each crossing area of horizontal electrodes and vertical electrodes when signals are applied via a switching device, to lead-out electrodes selectively. (Hereinafter, a luminescent area at the above crossing area is referred to as a pixel). Characters and graphics are displayed by choosing luminant pixels. In fabrication of the display panel of this type, transparent electrodes are formed on a transparent substrate such as a glass plate, then, a first dielectric layer, a phosphor layer and a second dielectric layer are stacked thereon successively and, further, back electrodes are formed on the second dielectric layer so as to cross the transparent electrodes orthogonally. Finally, lead-out electrodes are formed at predetermined positions. Usually, tin oxide or tin doped indium oxide (hereinafter referred to as ITO) is deposited on a flat glass substrate to form transparent electrodes. Metal films such as aluminum film and nickel film are formed as back electrodes and lead-out electrodes by a deposition method such as vacuum deposition.
The conventional forming methods of back electrodes and lead-out electrodes are as follows.